The present invention relates to a corded earplug and additionally to a method for making such a corded earplug.
In the prior art, corded earplugs are generally made by initially making an earplug by any conventional technique. The earplugs are either produced with an elongated opening at one end or an elongated opening is made at one end of the earplug after it has been produced. An adhesive is then applied to the opening and one end of a cord is inserted into the elongated opening, during the short time that the adhesive is liquid. This adhesive then bonds the cord within the opening at one end of the earplug and generally a pair of such earplugs is located at opposite ends of the cord. This produces the conventional type of corded earplug, which includes a number of additional steps after the earplugs are produced.
The difficulty with prior art corded earplugs is that it is difficult to insert the cord into the opening during the short period of time that the adhesive is liquid. In addition this method of attaching the cord to the earplug can result in a bond that is completely dependent on the adhesive and therefore may not be very strong. Also this method is permanent and does not allow for the pair of earplugs to be used without a cord. Other prior art corded earplugs use a cord with ends that can be inserted into an opening in the earplugs but are easily removable desired so that the earplugs can be used without the cord. Since the attachment of the cord to the earplugs is easily removable, the earplugs can be disengaged from the cord when this is not desired.
It would therefore be desirable to provide for a method of attaching a cord to an earplug using a method and apparatus that is simpler than the prior art and also produces strong connection between the cord and the earplug. In a prior application Ser. No. 12/924,462, filed Sep. 28, 2010, a method and apparatus fix overcoming the problems of the prior art were shown. This improved method and apparatus would work best if the cord was braided and included stiff end portions but, if the cord were a smooth plastic or a braided material without stiff end portions, then it would be more difficult to use the method and apparatus of this prior application.